Energy guiding chain

ABSTRACT

An energy guiding chain for guiding hoses, cables and the like has a number of chain links connected to one another in articulated fashion which are formed by parallel straps connected by cross-members. The energy guiding chain can be moved in such a way that it forms an upper strand, a lower strand and a deflection zone connecting the two, where the upper strand rests on the lower strand. In order that the upper strand can be moved lying on the lower strand with the least possible power and low wear, and the chain is of the simplest possible design, at least some of the chain links of the upper strand and/or the lower strand are provided with rollers that can roll on running surfaces provided on the chain links of the opposite strand when the energy guiding chain travels.

FIELD OF THE INVENTION

The invention relates to an energy guiding chain for guiding cables,hoses and the like, having a number of chain links connected to oneanother in articulated fashion which are formed by parallel strapsconnected by cross-members, which energy guiding chain can be moved insuch a way that it forms an upper strand, a lower strand and adeflection zone connecting the two, where the upper strand rests on thelower strand, and where at least some of the chain links of the upperstrand and/or the lower strand are provided with rollers which arearranged in such a way that, when the energy guiding chain travels, theycan roll on running surfaces provided on the chain links of the oppositestrand.

Furthermore, the invention relates to an energy guiding chain forguiding cables, hoses and the like, having a number of chain linksconnected to one another in articulated fashion which are formed byparallel straps connected by cross-members, which energy guiding chaincan be moved in such a way that it forms an upper strand, a lower strandand a deflection zone connecting the two, where the upper strand restson the lower strand.

BACKGROUND OF THE INVENTION

In some applications, energy guiding chains of this kind are of aconsiderable length which can be in the region of 100 meters or more.Thus, the drive must provide correspondingly high drive power in orderto move the energy guiding chain. This is especially the case if theupper strand of the energy guiding chain rests on the lower strandduring travel, as the corresponding sliding friction, which reaches asubstantial magnitude with very long energy guiding chains, has to beovercome. The respective sliding surfaces of the chain links are subjectto increased wear due to the friction between the upper strand and thelower strand.

As considerable tensile forces are required to move the energy guidingchain, a change in length also occurs in the energy guiding chain whichcan easily amount to up to roughly 8%, referred to the length of theunstressed chain. This change in length occurs as a result of theever-present play between the chain links and the ever-presentelasticity of the chain links. This elongation of the energy guidingchain generates corresponding stress on the hoses or the like guided bythe energy guiding chain.

It is common practice to provide special support structures forparticularly long energy guiding chains that support the upper strand sothat the upper strand can be moved on this support structure. In orderto facilitate the movement of the energy guiding chain, some of thechain links are provided with rollers that can roll along the supportstructure. However, the arrangement of support structures of this kindis very complex and, in addition, the support structure cannot be usedwhen moving an energy guiding chain in which the upper strand isarranged above the lower strand. In this case, it has been proposed todesign the support structure in such a way that the supporting memberscan be swung out to the side in order to be removed from the range ofmotion of the energy guiding chain. However, this requires acorresponding swivel mechanism, which requires appropriate maintenanceand also restricts the travel speed of the energy guiding chain. On thewhole, there are many fields of application of energy guiding chains inwhich support structures are not expedient, quite apart from thetechnical resources they require.

GB 1 444 307 A discloses an energy guiding chain in which the chainlinks are provided with supporting areas which are oriented in such away that they combine to form a flat surface. The supporting areas areprovided at the inner side of the loop of the energy guiding chain.Predetermined chain links are provided with supporting wheels whichprotrude beyond the plane of the adjacent supporting area, through arecess provided in the supporting area. An energy guiding chain is thusprovided by means of which the supporting forces can be dissipated viathe chain links in a favorable manner so that the chain links can be oflight construction and higher supporting forces can be distributed.

SUMMARY OF THE INVENTION

The object of the present invention is to design an energy guiding chainin which the upper strand can be moved lying on the lower strand withthe least possible power and low wear, and which is of the simplestpossible design, and by which a simply constructed guidance of theenergy transmission chain is provided, even in case of long energyguiding chains.

According to the invention, the object is solved in that the rollershave a guide profile, which is formed by several circumferential guidegrooves positioned at a distance from one another in the running surfaceof the rollers. By these features of the rollers according to thepresent invention the travel characteristics can be further improved andan emission of noise can be further reduced, furthermore, frictionbetween the lower strand and the upper strand can be lowered.Simultaneously, a reliable guidance of the energy guiding chain isprovided.

Furthermore, it is an object of the present invention to provide anenergy guiding chain having increased stability of the chain links,especially in case of long chain links.

According to the invention, this object is solved in that twocross-members at a distance from one another in the longitudinaldirection of the chain are provided on one narrow side of a chain link.

When the rollers of two chain links equipped with rollers running on topof one another meet, they become offset by roughly the width of onegroove due to the geometry of the guide grooves, so that the profiles ofthe meeting rollers mesh. The elasticity of the energy guiding chaineasily permits the upper strand and the lower strand to run slightlyoffset relative to one another. This offset roughly corresponds to thewidth of one guide groove. This advantageously prevents the convergenceof the two superposed strands when two rollers meet.

It is particularly advantageous if the depth of the guide grooves is atleast equal to the distance the roller projects beyond the runningsurface of the associated chain strap. The rollers then need no longerclimb up and down one another, and a considerable amount of tensileforce that would otherwise have to be applied to the upper strand iseliminated. Approaching rollers can simply pass through one another.

The guide grooves are expediently provided with a roughly trapezoidalcross-sectional profile, which ensures the correct alignment of therollers relative to one another.

In this context, the rollers in the sense of the invention should betaken as being elements that rotate when they contact the runningsurfaces and move relative to them. For example, areas on the chainstraps projecting out to the side can be provided as running surfaces.

As a result of these measures, the upper strand can travel directly onthe lower strand by means of the rollers, while the friction between theupper strand and the lower strand is dramatically reduced due to therollers provided in accordance with the invention. For example, thefriction of the energy guiding chain according to the invention isroughly 6 or more times less than that of a conventional energy guidingchain of similar design, meaning that the chain can be 6 or more timeslonger with the same drive.

Furthermore, as a result of the rollers provided, there is considerablyless elongation of the chain as compared to conventional energy guidingchains travelling at the same speed. The wear on the contact surfacesbetween the upper strand and the lower strand is also markedly reduced.

As the running surfaces for the rollers of the opposite strand arelocated directly on the chain links, it is possible to design the energyguiding chain to be particularly lightweight, meaning that the length ofthe energy guiding chain and its travel speed can be correspondinglyhigh.

The rollers can be directly mounted on the chain straps usingappropriate bearings, and the roller mount can be correspondinglystable. Thus, separate connectors are not required.

The rollers are preferably located in recesses provided on the chainstraps, with the rollers projecting at least slightly beyond the chainstraps towards the opposite strand. The axis of rotation of the rollersis located inside the cross-section of the chain straps.

The running surfaces for the rollers can be directly formed by thenarrow sides of the chain straps facing the opposite strand. In thiscontext, the chain straps can be designed in such a way that acontinuous running surface is formed when the energy guiding chain isextended, so that there are no or only slight differences in the levelof the running surface, particularly in the joint sections of the chainstraps.

The recesses for accommodating the rollers in the chain straps can be ofclosed design in the lateral direction of the chain straps, i.e.perpendicular to the longitudinal direction of the energy guiding chain.The pockets formed in this way, which are only open to one side, make itpossible to design an energy guiding chain with a completely enclosedinterior.

In order to ensure minimum surface pressure on the running surfaces, thewidth of the rollers should be as large as possible. To this end, thechain straps can, if necessary, be provided with wider sections ofcorresponding width in the region of the rollers, where the wallthickness of the chain straps can decrease towards the joint sections ortowards the longitudinal center of the chain straps.

One, two or more rollers can be provided on each narrow side of thechain straps, the rollers being spaced apart from one another in thelongitudinal direction of the energy guiding chain, so that the stresson the rollers and the bearings can be distributed over severaldifferent rollers in each case.

The straps can be connected by a cross-member positioned in the middleof the chain strap or midway between the two or more rollers, asappropriate. The narrow sides of opposing straps are preferablyconnected by two cross-members, which can, in particular, be located onthe side straps immediately adjacent to the joint or end sections, thusincreasing the stability of the chain links, particularly in the case oflong links. In this way, the straps can be connected by fourcross-members or, if appropriate, by only three or two cross-members. Itis particularly advantageous for the cross-members to be provided withwider sections on the side, which partially cover the inside of theadjacent strap. If top and bottom elements are to be provided on thecross-members, so that a completely closed cable channel results, thedistance between adjacent cross-members on one narrow side of the strapsand the strap length are advantageously twice as large as on the chainlinks without rollers. The links provided with rollers can thus befitted with twice as many standard top and bottom elements as the linksused previously, in order to form a closed channel without requiringspecial parts.

In another configuration, each chain strap can be provided with at leastone roller mounted in the middle of the chain strap, with cross-membersarranged in front of or behind the roller in the longitudinal directionof the energy guiding chain—preferably in front of and behind it. Aconfiguration with several cross-members is particularly advantageous ifthe chain straps are longer due to the rollers mounted on them.

In order to improve the travel characteristics of the energy guidingchain, the running surfaces can have run-up bevels rising towards therollers. In this way, the height of the rollers projecting beyond thechain straps can be reduced for any given arrangement of the axis ofrotation, this having an advantageous effect on the quiet running of theenergy guiding chain.

In order to mount the rollers in the recesses of the chain straps,flanges can be provided which have a bearing section for the rollers,where the flanges can have sections of greater radial dimensions inrelation to the axis of rotation of the rollers, these sections beingprovided with means for attaching the flanges to the chain straps. Therollers can be mounted on one or both sides of the flanges. The axlescan also be mounted on one side of the flange and on the oppositesection of the chain strap.

If the chain straps are provided with recesses for accommodating therollers, means can be provided with which the recesses can be bridged onthe side towards the opposite strand. This can be achieved by usingcorresponding caps, for example. This can prevent the rollers of onestrand from running into recesses in the chain links of the oppositestrand, if no rollers are mounted in these recesses.

In particular, standard chain links can also be provided between thechain links with rollers. In this way, the energy guiding chain canessentially consist of the previously known chain links, between whichchain links additionally provided with rollers are mounted at intervalsof several chain links, for example.

The chain straps can also be alternatively or additionally designed insuch a way that they are provided with recesses for accommodatingrollers on one of the narrow sides running parallel to the longitudinaldirection of the chain, where the opposite narrow side of the chainstrap has no recesses, and where the chain straps are designed in such away that they can be mounted with either of the narrow sides facing theopposite strand. The same chain strap can thus be optionally used forassembly with or without rollers. For this purpose, the chain strap needonly be rotated 180° about its longitudinal axis, or about the axiswhich extends through the center plane of the chain straps perpendicularto their longitudinal direction.

The links with rollers have a greater length, i.e. a greater pitch thanthe conventional chain links. Exceeding certain pitch dimensions is notdesirable, as this generates uneven running of the chain through thedeflection radius, especially when links with very different lengths areconnected in alternating fashion. Therefore, one configuration of theinvention provides that the rollers be mounted on the side of the chainstraps projecting outwards and that wider sections of the chain strapsprojecting out to the side be provided as running surfaces. In this way,the pitch of the chain links without rollers can be retained on chainlinks with rollers.

In a configuration of the energy guiding chain such as this, at leastall the chain straps of one strand—both the outer and inner straps—areexpediently provided with a wider section which forms a running surface,so that at least one essentially closed running surface is formed alongthe length of the energy guiding chain.

Each of the rollers can penetrate a window-like recess in the widersections which form the running surfaces.

The rollers can be distributed over the chain links in different ways.It is not always necessary to provide every chain link with rollers, sothe rollers can also be mounted on the energy guiding chain at intervalsof more than one chain link. In this context, an equal distance can beprovided between the rollers so that, for example, only every fourth,fifth, etc. chain link is provided with opposing rollers.

However, the rollers can also be distributed over the length of theenergy guiding chain at irregular intervals. Thus, the rollers can bedistributed at greater repeat periods, within which the distance betweenthe rollers can, for example, alternate, so that, starting at one chainlink, rollers can be mounted after three, then five, then three chainlinks, etc., in the longitudinal direction of the chain. In thiscontext, the distribution of the rollers over the chain links can alsobe random.

In addition, it is not necessary to provide both chain straps of thesame chain link with rollers, meaning that the distribution of therollers over the various strands of chain straps need not besymmetrical.

An irregular or asymmetrical distribution of the rollers has theadvantage that, at certain times during the movement of the energyguiding chain, not all the rollers are in contact with one anothersimultaneously, but rather only a few of them, where the time betweencontact of the rollers can vary. In this way, the slight jolts caused bythe meeting of the rollers can be distributed irregularly over theenergy guiding chain, so that jerky movements along the entire length ofthe energy guiding chain can be avoided when it is travelling rapidly.This can improve the quiet running of the energy guiding chain.

Depending on the operating conditions of the energy guiding chain, thechain straps can be provided with rollers that project beyond thelongitudinal axis of the chain straps on one side, on the opposite side,or on both sides of the chain straps. In this way, these rollers can beoptionally mounted in the region of the upper strand or the lower strandor, if the energy guiding chain can move on both sides of the end point,on both sides of the chain straps.

It is also particularly possible to provide rollers on energy guidingchains that have more than two parallel strands of chain straps, inwhich case rollers are to be provided on at least two strands. Forexample, the rollers can be located exclusively on the outer strands,and they can instead or additionally be provided on one or more of theinner strands of chain straps.

It is particularly advantageous if, in at least one area of the chainadjacent to the moving driver of the energy guiding chain, sections ofchain links are interconnected, and the chain link closest to the driveris connected to the driver in tension-resistant fashion by at least oneelement which is essentially inextensible in the longitudinal directionof the chain and flexible in the bending direction of the chain. Anelement of this kind is described in German Patent Application DE 198 07083, the entire contents of which are incorporated herein.

Because of the arrangement of the inextensible element on the energyguiding chain in combination with the arrangement of the rollers, thechain can be moved over very great lengths with minimum power andwithout elongating the energy guiding chain under tensile stress. Thisgenerally enables energy guiding chains of particularly great length tobe controlled and thus opens up new fields of application for energyguiding chains.

The sections in which the chain links connected by one or moreinextensible elements are arranged advantageously comprise several chainlinks. The sections can be of equal or unequal length. Unequal lengthsare preferably used, with the sections becoming shorter towards thedriver, because the tensile stress on the chain increases towards thedriver.

The inextensible element, or at least one of them if there are several,can be one of the lines guided in the chain. The inextensible element,or at least one of the inextensible elements, is preferably arrangedseparately from the lines. The element or elements arranged separatelyfrom the lines can be provided in the interior of the chain and consistsof steel cables, for example. However, any other kind of element thatdisplays these characteristics is also conceivable.

Adjacent ones of the chain links located at the ends of the individualsections are preferably interconnected, and the closest of these chainlinks to the driver if preferably connected to the driver intension-resistant fashion by at least one element which is inextensiblein the longitudinal direction of the chain and flexible in the bendingdirection of the chain.

The inextensible element(s) is/are preferably mounted intension-resistant fashion on strips arranged separately from thecross-members, the strips being connected to the opposing straps of thechain links.

The lines guided through the chain are advantageously secured to thesestrips by clamps, which can also be provided with fastening elements forthe ends of the steel cables or other appropriate inextensible elements.

The strips can have pins on the ends lying in the transverse directionof the chain, which assume the function of link pins for the associatedchain links. This means that the pins on the straps form a positiveconnection by reaching through two aligned openings in the overlappingareas of directly adjacent chain links and thus form the hinge axesbetween these chain links. This configuration permits the lines and theseparate inextensible elements mounted on the strips to be arranged inpivoting fashion about the hinge axes.

The strips can have projections on the ends lying in the transversedirection of the chain, which engage correspondingly shaped grooves onthe inside of the chain links between the joint sections. The groovesprovided in all chain links of a chain series can also be used to mountother parts between the chain straps.

The energy guiding chains according to the invention can consist ofinner and outer straps, as well as angled chain links. The cross-memberscan in each case be mounted in detachable fashion on the side straps orintegrally molded on them, or they can be of such a width that they forma closed channel. The joint connections can be of any design, such asintegral hinges or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described in detail below and an example explainedbased on the drawings. The drawings show the following:

FIGS. 1a-1 d, herein collectively referred to as FIG. 1, illustratedifferent views of an outer strap of an energy guiding chain accordingto the invention,

FIGS. 2a-2 d, herein collectively referred to as FIG. 2, illustratedifferent views of an inner strap of an energy guiding chain accordingto the invention,

FIGS. 3a-3 d, herein collectively referred to as FIG. 3, illustrate asecond configuration of an outer strap,

FIGS. 4a and 4 b, herein collectively referred to as FIG. 4, illustratea cross-section of a chain strap taken through a roller,

FIG. 5 A top view of a section of an energy guiding chain,

FIGS. 6a-6 c, herein collectively referred to as FIG. 6, illustrate sideviews of three energy guiding chains with the upper strand resting onthe lower strand and different roller distributions,

FIGS. 7 and 8 Enlarged views of an energy guiding chain according toFIG. 6 in different travel positions,

FIGS. 9a and 9 b, herein collectively referred to as FIG. 9, illustratea cross-section of an energy guiding chain with the upper strand restingon the lower strand in different travel positions,

FIGS. 10a and 10 b, herein collectively referred to as FIG. 10,illustrate a side view of an energy guiding chain with an inextensibleelement connecting the driver and chain links,

FIG. 11 A view of a second configuration of the energy guiding chainaccording to the invention with the upper strand resting on the lowerstrand, where the rollers are located on the side of the chain strapsprojecting outward,

FIG. 12 A partially cut-away view of the illustration in FIG. 11,

FIGS. 13 and 14 Side views of an energy guiding chain with the upperstrand resting on the lower strand according to the second practicalexample of the invention,

FIG. 15 An illustration of an energy guiding chain with the upper strandresting on the lower strand according to a third practical example ofthe invention, in which the rollers have a profile,

FIG. 16 A partially cut-away view of the illustration in FIG. 15, and

FIGS. 17 and 18 A side view of the energy guiding chain according to thethird practical example of the invention in different travel positionsof the energy guiding chain.

DETAILED DESCRIPTION OF THE DRAWINGS

The chain strap 1 shown in FIG. 1 is designed as an outer strap, whichis connected to an inner strap 2 (shown in FIG. 2) in articulatedfashion to form a strand. For this purpose, link pins 5 are provided onend sections 3, 4 of outer straps 1 and corresponding pin guides 8 onend sections 6, 7 of inner straps 2, as well as corresponding pairs ofstops 9, 10 to restrict the swivel angle.

Straps 1, 2 are each symmetrical about the center plane perpendicular tothe longitudinal axis of the straps.

Middle sections 11, 12 of chain straps 1, 2 are designed as widesections and merge on the side of straps 1, 2 facing away from the chaininterior, via bevels 13, 14 running perpendicular to the longitudinalaxis of the straps, into end sections 2, 3.

A roller 15 is mounted in rotating fashion in an arc-shaped recess 15 ain middle section 11 of outer strap 1 by means of a flange 16. Axle 17of the roller is fixed at one end by flange 16 and at the opposite endin a recess in the chain strap.

Protruding area 18 of roller 15 can roll over a running surface locatedon the chain links of the opposite strand, so that the upper strand canmove lying on the lower strand.

In the embodiment, narrow sides 19 of the chain straps (see FIG. 9)serve as running surfaces for the rollers of the opposite strand andessentially extend between the swivel axes of adjacent chain linksdefined by the joint sections (FIGS. 6 to 8). This ensures that, whenthe energy guiding chain is extended, no dips are formed between therunning surface sections 26 of adjacent chain straps level with thejoint connections, thus resulting in a continuous running surface forthe rollers over the length of the chain with very little or nodifferences in height.

Running surface or side surface 19 has run-up bevels 20 extending in thelongitudinal direction of the energy guiding chain and positioned beforeand after roller 15, which rise towards rollers 15 and essentially startlevel with the swivel axes of the straps. In this context, the slope ofrun-up bevels 20 is relatively small and can, for example, climb aheight of about 3 mm over a length of 80 mm. Area 18 of roller 15projects above the apex of run-up bevel 20 by about another 2 mm.

The inner straps, and the narrow sides of the outer straps withoutrollers, do not have any run-up bevels in the embodiments shown.

In the practical example shown, the diameter of rollers 15 isessentially half the height of chain strap 1.

Thus, the run-up angle to the rollers (angle between the circumferentialsurface of the roller and the run-up bevel) is relatively small.However, rollers with a considerably smaller diameter relative to theheight of the chain straps can also be used.

Due to the widening of middle sections 11, 12 of chain straps 1, 2, itis also possible to widen the running surface for the rollers at thislocation, which results in less surface pressure on narrow sides 19 ofthe chain straps and thus in a further reduction of the material stress.

As FIGS. 1, 2, 3 and 5 also show, pairs of pins 21 for mountingcross-members 22 are arranged level with the widened middle sections 11,12 at a substantial distance from one another, so that opposing innerand outer straps are connected by four cross-members, thus increasingthe stability of the chain links. The pins 21 on the outer strap arearranged before and after roller 15 in the longitudinal direction of theenergy guiding chain. Cross-members 22 of the inner straps are alsomounted at a distance from one another (FIG. 5). If the opposite side ofchain strap 1 is not provided with a roller (as shown), the chain strapson this side can also be optionally connected by a single cross-memberpositioned level with the roller.

According to the embodiment in FIG. 3, two (or possibly more) rollerscan also be mounted in series on one chain strap. The rollers areattached to the wider section by way of flanges in this embodiment also.As on the chain straps in FIGS. 1 and 2, cross-members 22 are arrangedat the ends of the wider section. They can, if necessary, also beprovided between the rollers. The running surface section betweenrollers 15 runs parallel to the opposing narrow side of the strap.

As shown in FIGS. 4 and 9, rollers 15 roll over narrow sides 19 of chainstraps 1 of the opposite strand until they come into contact with therollers of the opposite strand and roll over them.

FIGS. 4 and 9 also show that one end of axle 17 of the roller is fixedby flange 16 and the opposite end by in recess 15 a in the chain strap.The axle has a bearing race 24 of a ball bearing 25. Flanges 16 aremounted in non-rotating fashion on the chain straps by three studs 23and are completely flush with strap 1, so that the flanges do notprotrude to the side. In this context, rollers 15 take up about half thewidth of the chain straps. Flanges 11 can also be designed in such a waythat they essentially enclose rollers 12.

The mounting of rollers 15 directly on the chain straps by means offlanges 11 results in particularly stable roller mounting. The rollersare located inside the cross-section of the energy guiding chain and theaxes of rotation inside the cross-section of the chain straps, thusavoiding protruding regions.

Due to the fact that the height of areas 18 protruding beyond narrowsides 19 of chain straps 1 is relatively small compared to the diameterof rollers 15, it is possible to operate the energy guiding chainextremely quietly and smoothly.

As shown in FIG. 4 (bottom), when the roller is dismounted, the openingfacing the respective narrow side 19 of the chain link can be coveredwith a cap 25 a and snap elements 25 b can be provided on the side strapin order to attach it, while the mounting elements for the roller canpossibly remain assembled. The same cap or a separate one can possiblyalso be used to cover the side area of the side piece which serves toaccommodate the mounting elements of the roller. The cap can be flushwith the respective outside surface of the side strap.

As shown in FIG. 5, two cross-members 22 are arranged immediatelyadjacent to end sections 3, 4 on inner and outer straps. Wider sections36 on the ends of cross-members 22 on outer straps 1 overlap the insideof end sections 4 of the inner straps with only little play, so thatthis overlap increases the stability of the chain.

In order to be able to move the upper strand on the lower strand bymeans of rollers 15 with little power, it is (as shown in FIG. 6) notnecessary to provide every chain strap of energy guiding chain 27 withrollers. Rather, they can be spaced apart from one another on the chainstraps, e.g. every third or fourth chain link. If the rollers arearranged closely, e.g. on every chain link, the rollers come intocontact with the lower strand 29 first during the transition fromdeflection zone 30 to upper strand 28, thus avoiding sliding friction.

In the same energy guiding chain 27, chain links with rollers 38 canalso be provided which are longer than chain links without rollers 37(FIG. 6).

As shown in FIGS. 6 to 8, in a sufficiently stable energy guiding chain,the superposed upper strand is arranged in self-supporting fashion dueto the slightly protruding rollers and rests on the lower strand onlyvia the rollers, thus resulting in particularly low friction values inthe event of relative motion of the upper and lower strand. Run-upbevels 20 (FIG. 7) expand the gap between the chain strands.

As another component which is of particular importance in connectionwith the rollers, the energy guiding chain can be fitted with a steelcable which is inextensible in the longitudinal direction of the chainand flexible in the bending direction of the chain, as shown in FIG. 10.

The illustration in FIG. 10 shows an energy guiding chain 27 foraccommodating and guiding lines 31 between a stationary base 32 and amobile driver 33 with two parallel strap strands consisting of opposingstraps 1 in the transverse direction which are connected to one anotherby cross-members (not shown in FIG. 10). The immediately adjacent straps1 a and 1 b of each strap strand can swivel relative to one another inthe bending direction of the chain.

As is further shown in FIG. 10, one section of the chain, which extendsfrom driver 33 over the upper strand and the bending region all the wayto the lower strand of the chain, is equipped with elements 34 (34 a, 34b, 34 c, 34 d, 34 e, 34 f and 34 g) which are inextensible and flexiblein the bending direction of the chain. These elements interconnect chainlinks 35 a, 35 b, 35 c, 35 d, 35 e, 35 f and 35 g, which are mounted inthe associated region of the chain separated from one another and fromdriver 33 by several chain links. Chain link 35 a closest to driver 33is connected to driver 33 via inextensible element 34 a.

FIG. 11 shows a second embodiment of the energy guiding chain accordingto the invention. Here, rollers 15 are mounted on the outside of chainstraps 1, 2. Rollers 15 are not covered. Wider sections 39 with anL-shaped cross-section, which are provided on the side of outer straps 1and inner straps 2, serve as running surfaces and have window-likeopenings on those chain links 38 that have rollers 15, through whichopenings the rollers 15 project. The arrangement of rollers 15 on theoutside of chain straps 1, 2 beyond the chain cross-section has theadvantage that the pitch of chain links 38 with rollers can be smaller,i.e. as small as the pitch of chain links 37 without rollers.

As is shown particularly clearly in the cut-away view in FIG. 12,rollers 15 are accommodated by ball bearings 25 (shown only roughly inthe illustration), which are secured by means of a circlip 42 on abearing pin 41 integrally molded on the outside of the associated chainstrap 1.

Wider sections 39 with an L-shaped cross-section, which are provided onouter straps 1 and on inner straps 2 of both strap strands, each form aclosed running surface for rollers 15 in the longitudinal direction,where, in this configuration, run-up bevels rising towards rollers 15can also be provided, as can be seen in FIGS. 13 and 14.

FIGS. 13 and 14 show two different travel positions of the energyguiding chain, i.e. two different relative positions of chain links 38with rollers. FIG. 14 shows chain links 38 with rollers in a laterallyoffset position. When rollers 15 of upper strand 28 and lower strand 29meet, as shown in FIG. 13, upper strand 28 must rise in relation tolower strand 29, because roller 15 shown in upper strand 28 has to“climb” over run-up bevel 20 and roller 15 in lower strand 29. Run-upbevel 20 minimizes the projection of rollers 15 above the runningsurfaces of wider sections 39, so that rollers 15 do not jump over oneanother in jerky fashion, which would cause uneven running of the energyguiding chain.

FIGS. 15 to 18 show a particularly advantageous third embodiment of theenergy guiding chain according to the invention, in which rollers 15 areprovided with a guide profile, i.e. several all-round guide grooves 40with a trapezoidal cross-sectional profile which are spaced apart fromone another. Ridges 43 remaining between guide grooves 40 of twocontacting rollers meet frontally which, because of the trapezoidalcross-section of the guide grooves, leads to a lateral offset in therelative position of upper strand 28 and lower strand 29, as shown inFIG. 15. This offset is roughly equal to the width of one guide groove40, so that the rollers of upper strand 28 pass through those of lowerstrand 29. For this purpose, the depth of guide grooves 40 must, ofcourse, be greater than or equal to the distance of rollers 15 from therunning surfaces formed by wider sections 39.

The elasticity of the energy guiding chain easily permits upper strand28 and lower strand 29 to be in an offset position of this kind over arelatively great distance, this ensuring extremely low friction values.

As is particularly clearly shown in FIG. 17, the rollers of the chainlinks of upper strand 28 pass through the chain links of lower strand 29when the two meet.

The chain straps and rollers are preferably made of plastic. However,other combinations of materials are also possible. For example, thechain straps and/or rollers can also be made of metallic materials.

List of Reference Numbers

1 Outer strap

2 Inner strap

3, 4 End section

5 Linkpin

6, 7 End section

8 Pin guide

9, 10 Pairs of stops

11, 12 Middle section

13, 14 Bevels

15 Roller

15 a Recess

16 Flange

17 Rotation axle

18 Area

19 Narrow side

20 Run-up bevel

21 Pin

22 Cross-member

23 Stud

24 Bearing shell

25 Ball bearing

25 a Cap

25 b Snap elements

26 Running surface section

27 Energy guiding chain

28 Upper strand

29 Lower strand

30 Deflection zone

31 Lines

32 Base

33 Driver

34 Inextensible element

35 Chain link

36 Wider section

37 Chain link without rollers

38 Chain link with rollers

39 Wider sections of the chain straps

40 Guide grooves

41 Bearing pin

42 Circlip

43 Ridges

What is claimed is:
 1. An energy guiding chain for guiding cables orhoses comprising: chain links connected to one another in articulatedfashion in such a way that said chain can be disposed to form a lowerstrand, an upper strand resting on said lower strand, and a deflectionzone connecting said upper and lower strands, and said upper strand canmove along said lower strand, said links comprising: parallel straps,and cross-members connecting said straps, said chain links definingrunning surfaces on at least one of said upper strand and said lowerstrand; and rollers so arranged on at least some of the chain links ofat least one of said upper strand and said lower strand that, when theenergy guiding chain travels, they can roll on said running surfacesprovided on the chain links of the other of said upper strand and saidlower strand; wherein the rollers have a guide profile, which is formedby several all-round guide grooves positioned at a distance from oneanother in the running surfaces of the rollers.
 2. Energy guiding chainaccording to claim 1, wherein a chain link comprises two saidcross-members provided on one narrow side of a strap of said chain link,and said two cross-members are directly adjacent to the joint sectionsof said chain strap.
 3. Energy guiding chain according to claim 1,wherein the cross members are provided with lateral wider sections whichpartially cover the inner side of the straps connected by saidcross-members.
 4. Energy guiding chain according to claim 1, wherein thedepth of the guide grooves is at least equal to the distance the rollersproject.
 5. Energy guiding chain according to claim 1, wherein therunning surfaces provided on the chain links are formed by the narrowsides of the chain straps facing the opposite strand.
 6. Energy guidingchain according to claim 1, wherein the rollers are located in openingsprovided on the chain straps and project at least slightly beyond thechain straps.
 7. Energy guiding chain according to claim 1, wherein atleast two rollers, which are spaced apart from one another in thelongitudinal direction of the energy guiding chain, are provided on eachchain strap.
 8. Energy guiding chain according to claim 1, wherein atleast one roller is mounted on each chain strap in a middle section ofthe chain strap.
 9. Energy guiding chain according to claim 1, whereinthe running surfaces have run-up bevels rising towards the rollers. 10.Energy guiding chain according to claim 1, wherein the rollers aremounted in recesses in the chain straps by flanges having a bearingsection for the rollers.
 11. Energy guiding chain according to claim 6,wherein some said chain straps have said openings without rollers, andmeans are for bridging said openings without rollers.
 12. Energy guidingchain according to claim 1, comprising chain straps which have anopening for accommodating a roller on one of the narrow sides and have acontinuous running surface on the opposite narrow side, and wherein saidchain straps are arranged to be mounted with either of the two narrowsides facing the opposite strand.
 13. Energy guiding chain according toclaim 1, wherein two cross-members at a distance from one another in thelongitudinal direction of the chain are provided on one narrow side of achain link.
 14. Energy guiding chain according to claim 1, wherein therollers are mounted on the side of the chain straps projecting outwardsand in that wider sections of the chain straps projecting out to theside are provided as running surfaces.
 15. Energy guiding chainaccording to claim 14, wherein at least all the chain straps of onestrand are provided with said wider sections which form a runningsurface, so that at least one essentially closed running surface isformed along the length of the energy guiding chain.
 16. Energy guidingchain according to claim 14, wherein each of the rollers penetrates awindow-like opening in the wider sections which form the runningsurfaces.
 17. Energy guiding chain according to claim 1, wherein thechain links with rollers are mounted at intervals of more than one chainlink.
 18. Energy guiding chain according to claim 1, wherein the chainlinks with rollers are distributed over the length of the energy guidingchain at irregular intervals.
 19. Energy guiding chain according toclaim 1, wherein the guide grooves have a trapezoidal cross-sectionalprofile.
 20. Energy guiding chain according to claim 1, wherein morethan two parallel strands of chain straps are provided, and wherein saidrollers are provided on at least two strands.
 21. Energy guiding chainaccording to claim 1, for accommodating and guiding lines between astationary base and a mobile driver, comprising two parallel strapstrands consisting of opposing straps and cross-members connecting saidstrap strands to one another in the transverse direction, wherein theimmediately adjacent straps of each strap strand can swivel relative toone another in a bending direction of the chain, wherein sections ofchain links in at least one area of the chain adjacent to the driverchain links are interconnected in sections, and the one of these chainlinks closest to the driver is connected to the driver intension-resisting fashion by at least one element which is essentiallyinextensible in the longitudinal direction of the chain and is flexiblein the bending direction of the chain.
 22. An energy guiding chain forguiding cables or hoses, comprising: chain links connected to oneanother in articulated fashion in such a way that said chain can bedisposed to form a lower strand, an upper strand resting on said lowerstrand, and a deflection zone connecting said upper and lower strands,and said upper strand can move along said lower strand, said linksdefining narrow sides that face the chain links of the other of saidupper strand and said lower strand, and comprising: parallel straps, andtwo cross-members on each said link connecting said straps at a distancefrom one another in the longitudinal direction of the chain on onenarrow side of a chain link, said chain links defining running surfaceson at least one of said upper strand and said lower strand; and rollersso arranged on at least some of the chain links of at least one of saidupper strand and said lower strand that, when the energy guiding chaintravels, they can roll on said running surfaces provided on the chainlinks of the other of said upper strand and said lower strand. 23.Energy guiding chain according to claim 22, wherein the rollers have aguide profile, which is formed by several all-round guide groovespositioned at a distance from one another in the running surfaces of therollers.